This invention is concerned with the use of thyrotropin releasing hormone (TRH) or a related tripeptide as a growth promotant for poultry.
The United States broiler chicken industry has been quite successful in providing high protein meat at relatively low cost to the consumer. Nonetheless it is always striving to improve the efficiency of its operations to make the industry more profitable and/or decrease the market cost of the product. There are several factors that can be explored toward this end such as improving feed efficiency, and one very important factor, the length of time required to produce a marketable bird from a chick. Clearly the shorter the time the better.
At present, broiler chickens in the United States grow at their maximum exponential rate until they are about 4 weeks of age and their growth rate progressively decreases thereafter. Since chickens are usually slaughtered at 6 to 8 weeks of age their rate of growth during the final weeks is less than maximum. Thus one way of promoting the growth of broiler chickens would be to manipulate their endocrine system so that the period of most rapid growth is prolonged. Such a growth promotant would increase the growth rate of chickens older than approximately four weeks and would thereby decrease the time required to produce a bird of marketable weight.
Other growth promotants have been used in efforts to reduce the time of maturation of poultry such as certain antibiotics including bacitracin and tylosin with the usual onus that attaches to the use of antibiotics for such purposes. However, the industry has never had access to an endocrine mediated growth promotant and especially one devoid of safety problems.
Other commercial fowl production, although not on the same scale as the broiler industry would also benefit from the same improvements in efficiency.
Now, with the present invention, there is provided a method of promoting the growth of poultry. This method comprises the administration of TRH or a related tripeptide to poultry starting at about the time when their initial rapid growth rate begins to decrease and continuing until the desired final weight is attained. In the case of broiler chickens administration would normally begin at about 4 weeks of age and would continue until 6-8 weeks of age.